Rapid review of multisystem inflammatory syndrome in paediatrics: What we know one year later

Abstract

Background: : Multisystem inflammatory syndrome in children (MIS-C) associated with coronavirus disease 2019 (COVID-19) is an emerging condition that was first identified in paediatrics at the onset of the COVID-19 pandemic. The condition is also known as pediatric inflammatory multisystem syndrome temporally associated with severe acute respiratory syndrome coronavirus 2 (PIMS-TS or PIMS), and multiple definitions have been established for this condition that share overlapping features with Kawasaki Disease and toxic shock syndrome.

Methods: : A review was conducted to identify literature describing the epidemiology of MIS-C, published up until March 9, 2021. A database established at the Public Health Agency of Canada with COVID-19 literature was searched for articles referencing MIS-C, PIMS or Kawasaki Disease in relation to COVID-19.

Results: : A total of 195 out of 988 articles were included in the review. The median age of MIS-C patients was between seven and 10 years of age, although children of all ages (and adults) can be affected. Multisystem inflammatory syndrome in children disproportionately affected males (58% patients), and Black and Hispanic children seem to be at an elevated risk for developing MIS-C. Roughly 62% of MIS-C patients required admission to an intensive care unit, with one in five patients requiring mechanical ventilation. Between 0% and 2% of MIS-C patients died, depending on the population and available interventions.

Conclusion: : Multisystem inflammatory syndrome in children can affect children of all ages. A significant proportion of patients required intensive care unit and mechanical ventilation and 0%-2% of cases resulted in fatalities. More evidence is needed on the role of race, ethnicity and comorbidities in the development of MIS-C.

Keywords: COVID-19; Keywords: multisystem inflammatory syndrome in children; MIS-C; PIMS; PIMS-TS; pediatric multisystem inflammatory syndrome.

Figure 1

Article exclusion tree Abbreviation: MIS-C, multisystem inflammatory syndrome in children

Figure 2

Median age of multisystem inflammatory syndrome in children cases presented in cohort articles (n=72)

Figure 3

Age of multisystem inflammatory syndrome in children patients reported in case report articles (n=101, MIS-C cases=185) Abbreviation: MIS-C, multisystem inflammatory syndrome in children

Figure 4

Relationship^a between general population, COVID-19 and MIS-C cases Abbreviations: COVID-19, coronavirus disease 2019; MIS-C, multisystem inflammatory syndrome in children ^a There is evidence that racial and ethnic minority groups are disproportionately affected by COVID-19 (arrow 1). The effect of race and ethnicity on arrow 2 is less clear

Figure 5

Percent of cases of multisystem inflammatory syndrome in paediatric patients admitted to ICU/PICU in cohort articles where ICU/PICU admission was not required by the study design (n=56) Abbreviations: ICU, intensive care unit; PICU, paediatric intensive care unit

Figure 6

Percent of cases of multisystem inflammatory syndrome in paediatrics patients that were intubated in cohort articles where the study design did not require ICU/PICU admission (n=45) Abbreviations: ICU, intensive care unit; PICU, paediatric intensive care unit